Remove unnecessary template name declaration

This code was duplicate with the name we use to `register` the
component. A update of blaze-component removed the need to duplicate
this declaration.

client/components/import/import.js

@@ -7,10 +7,6 @@
 /// - getLabel(): i18n key for the text displayed in the popup, usually to
 /// explain how to get the data out of the source system.
 const ImportPopup = BlazeComponent.extendComponent({
-  template() {
-    return 'importPopup';
-  },
-
   jsonText() {
     return Session.get('import.text');
   },